40 denier tights are a mid-weight pair: more covering than a bare sheer, lighter than a full opaque. At 40 denier the leg is evened out and warmed without vanishing under a solid block of colour, which is why it is the weight many women reach for first. Heist knits its everyday mid-weight at 35 denier, The Thirty-Five, and steps up to 60 denier, The Sixty, when you want full cover.
Here is what 40 denier looks like on, whether it is see-through, and how to choose between a semi-sheer and an opaque. Every pair here is knit as a single seamless piece with a hand-sewn adaptive waistband, so it sits flat and holds its place all day.
What does 40 denier mean?
Denier measures the weight of the yarn: the higher the number, the denser the knit and the more it covers. Under 25 denier reads as sheer. From 30 to 50 denier you are in semi-sheer territory, the everyday mid-weight, and 40 denier sits in the middle of it. From 60 denier up, tights read as opaque, a solid block with no skin showing through.
At 40 denier the leg looks smooth and even, tone knocked back rather than hidden. It is warm enough for spring and autumn and light enough that it never feels heavy. For a day that runs from desk to dinner, this is the weight that carries it.
The Heist mid-weight, by colour
The Thirty-Five in Black
35 denier semi-sheer, knit from Q-Nova® by Fulgar recycled polyamide. Ladder-resistant, seamless and gusset-free.
Good for: everyday wear from desk to dinner.
The Thirty-Five in Chocolate Brown
35 denier semi-sheer in a soft chocolate brown, a warmer alternative to black with a little skin left showing.
Good for: brown and camel tones through autumn.
The Thirty-Five in Midnight Navy
35 denier semi-sheer in deep navy, the quiet way to wear colour with tailoring.
Good for: navy and grey suiting.
The Sixty in Black
60 denier opaque, our bestseller. Fully covering and soft, knit from recycled Q-Nova® yarn.
Good for: when you want no skin showing.
40 denier or 60 denier: which to choose
Choose a semi-sheer mid-weight when you want the leg covered but still natural, round most of the year and into milder evenings. Choose a 60 denier opaque when you want full cover and warmth, a solid black from autumn through winter. Between the two, start with the mid-weight. It is the easiest to wear and the hardest to get wrong.
Going lighter still, a true sheer under 25 denier is the barely-there option for warm weather and dressier looks. For the full weight-by-weight breakdown, read denier decoded.
Why a good mid-weight lasts
Two things decide whether a pair stays in your drawer or ends up in the bin. The first is the waistband. Ours is a hand-sewn adaptive waistband that sits flat at the natural waist, so it does not dig, roll or slide down through the day. The second is the knit. We tested 196 samples on 67 women over a year of development to get the fit and durability right, then knit every pair as a single seamless piece with anti-snag fusion technology, so a catch does not turn into a run.
That is the case for one good pair over three cheap ones: a lower cost per wear, and a leg that looks the same in March as it did in September.
How to wear 40 denier through the seasons
A semi-sheer mid-weight is the one pair that works almost year round. Through summer it takes the edge off bare legs under a dress without the heat of an opaque; see our guide to tights in summer. Into autumn it carries tailoring, boots and a midi skirt.
Black is the safe start, but a chocolate brown or a midnight navy reads quietly against camel, grey and denim. For more on wearing colour on the leg, read coloured tights.
40 denier tights: your questions answered
What does denier mean in tights?
Denier measures the weight of the yarn used to knit the tights. The higher the number, the denser and more covering the pair. Under 25 denier is sheer, 30 to 50 denier is semi-sheer, and 60 denier and above is opaque.
Are 40 denier tights see-through?
Only just. At 40 denier the leg is largely covered and evened out, though a little skin can read in bright light. For no show at all, step up to a 60 denier opaque.
What denier are semi-sheer tights?
Semi-sheer tights run from about 30 to 50 denier, with 40 denier in the middle. Heist knits its semi-sheer mid-weight at 35 denier, The Thirty-Five.
Are 40 denier tights warm enough for winter?
For milder winter days, yes. For cold weather you will want a 60 denier or higher opaque, which is denser and holds more warmth. See our guide to warm tights for winter.
What is the difference between 40 and 60 denier tights?
Coverage and warmth. A 40 denier semi-sheer covers the leg while keeping it natural. A 60 denier opaque is a solid block of colour with no skin showing and more warmth. Most wardrobes want one of each.
What are the best 40 denier tights in the UK?
Heist knits its mid-weight at 35 denier, The Thirty-Five: semi-sheer, ladder-resistant, seamless and gusset-free, in recycled Q-Nova® yarn. For fuller cover, The Sixty steps up to 60 denier.
Words by The Heist Team.
